Dual temperature water heating and supply system



L. F. LOWE Nov. 7, 1967 DUAL TEMPERATURE WATER HEATING AND SUPPLY SYSTEM Filed Dec. 22, 1965 INVENTOR. LEONARD F- LOWE MM ATTORNEYS United States Patent 3,351,130 DUAL TEMPERATURE WATER HEATING AND SUPPLY SYSTEM Leonard F. Lowe, East Stroudsburg, Pa., assignor to The Patterson-Kelley Co., Inc., East Stroudsburg, Pa. Filed Dec. 22, 1965, Ser. No. 515,794 8 Claims. (Cl. 165-39) ABSTRACT OF THE DISCLOSURE An apparatus capable of delivering hot water of two different temperatures consisting of a single container having a first water heating means associated with said container to heat the water in said container to one temperature and a second water heating means associated with said container to heat the water to a higher temperature and inlet and outlet means associated with said container and said heating means to convey water to and from said container and said heating means.

This invention relates to storage water heater systems, and more particularly to systems providing constantly available supplies of water deliverable at different temperatures.

A primary object of the present invention is to provide a single tank system incorporating an improved multi-stage heating and water storage and transport arrangement from which requisite quantities of water at various prescribed temperatures may be selectively drawn ofI" at will; whereby substantial installation investment and operational and maintenance economies may be realized compared to conventional systems for similar purposes.

Another object of the invention is to provide an improved water storage and heating device as aforesaid which automatically supplies water at the desired temperatures while drawing upon the heat source only as needed to efiiciently comply with the heated water demands.

Another object is to provide an improved heating system as aforesaid which will automatically and constantly furnish water uniformly heated to the prescribed temperatures.

Another object is to provide a system as aforesaid which will economically furnish heated water in the quantities required, regardless of sudden or erratic demands therefor.

Other objects and advantages of the invention will appear from the specification hereinafter and the accompany drawing wherein:

FIG. 1 is a vertical sectional view through a combination water storage and heating apparatus of the invention.

Generally stated, the invention contemplates an improved means for heating and storing water in a single, minimum sized accumulator tank; whereby water at different temperatures is available to supply (through separate outlets) either constant or intermittent and/ or either small or large quantity demands. The device may be readily constructed in unit form, fully self-contained and requiring minimum floor space; and is therefore suitable for installation in out-of-way locations. It may be readily connected to existing piping systems, and normally draws upon the associated steam generating :boiler in such limited manner as to avoid interference with constant steam pressures at the other associated steam operated equipment. Hence the boiler load is leveled off, thereby improving the boiler efficiency and life span. The above stated and other advantages of the apparatus of the invention will be apparent from the following description of an exemplary embodiment of the invention in a storage water heater unit as illustrated in the accompanying drawing.

As shown therein, the system may comprise a single tank as illustrated at 10 which is of cylindrical form and supported to lie horizontally; but is to be understood that the tank 10 may in lieu thereof be provided of any other preferred shape or form and may stand in any other attitude and be supported in any manner as preferred. In any case, the tank will include provision for connection to a cold water supply conduit 12 as indicated at 14; the low temperature heated water outlet connection being indicated at 15. As shown herein, the system is constructed to separately furnish heated water at two different temperatures (hereinafter referred to as high and low temperatures, respectively) and accordingly a pair of immersion type heater units designated generally at 16, 18 respectively, are provided to extend substantially into the tank 10 at different levels therein.

The heat exchange units 16, 18 are illustrated in the drawing herewith as each comprising an elongated casing or shroud 20, which is welded or otherwise alfixed to the wall of the tank 10, where it extends into the tank. In each case a tube sheet as indicated at 22 carrying the terminal ends of a bank of reverse bent tubes 24 is attached to the flanged outer end opening of the shroud 20. Bafiie plates 26 disposed vertically and alternately occupying upper and lower portions of the casing 20, function simultaneously as vertical supports for the tubes 24 and as liquid passageway guide devices so as to cause the water circulating through the casing 20 to pursue a zig-zag path around the heat exchange tubes 24. The baflles 26 also control the velocity of water flow through the heater.

A manifold cover or bonnet as indicated at 28 is fixed to the outer face of each tube sheet 22, and is provided with an internal partition rib 29; the rib being dimensioned to bear firmly against the tube sheet when the unit is in assembly so as to thereby divide the bonnet into two sections, as shown in the drawing. Thus, it will be appreciated that the tubes 24 may be initially assembled upon the tube sheet 22 and that this subassembly may then be slip-fitted into the shroud 20, and the tube sheet and bonnet assembly may then be firmly fixed in place to complete the mounting of the heat exchange unit in the tank. In each case a live steam or other heated fluid inlet conduit as indicated at 30 is arranged to deliver heating fluid into the bonnet 28 under control of valves 32, 33, respectively; the return outlets for spent steam being indicated at 34 and leading to steam traps as shown at 36.

In addition to the low temperature heated water draw-off connection as shown at 15, a second or high temperature draw-off connection as indicated at 40 is provided in communciation with the outer end of the shroud enclosing the upper heating unit 18. Thus, it will be appreciated that upon withdrawal of water from the interior of the tank 10, either from outlet 15 or outlet 4%, cold water will replace it through the conduit 12 and will flow thence into the outer end of the bottom casing 20 wherefrom it will proceed to flow rearwardly in a vertically zig-za-g path in heat-exchange relation with the tubes 24 until it emerges from the open inner end of the casing 20 and circulates upwardly into the main body portion of the storage tank 10. As indicated at 44, a temperature sensing bulb of conventional form is disposed to extend into the main body of the tank 10 in the lower region thereof, and the bulb 44, through a connection tube 46 operates a control device 48 so as to automatically adjust the steam flow control valve 32 so as to call upon the supply of steam as, and whenever, it may be required to maintain the temperature of the main body of water within the tank within the prescribed range of temperatures therefor.

To assist in maintaining the body of water residing in the main portion of the tank at substantially uniform temperature throughout its various levels, (as dictated by setting of the control for the steam valve 32) a constantly operating circulating" pump as indicated at 50 may be coupled in connection with a conduit system as shown at 52, 54, to pull the cooler water from the tank and deliver it into the intake 14 so as to recirculate through the lowermost tube bundle. Thus, it will be appreciated that the tank will carry a supply of uniformly heated (at low temperature) water readily available to be withdrawn at outlet 15; and that whenever water is withdrawn therefrom a corresponding supply of makeup water will pass through conduit 12 into the lower heater unit and thence into the tank.

The second or high temperature water outlet connection 40 is coupled with a conduit-housing 60 having a branch outlet 62 from which water may be drawn; and a sensing bulb 64 is mounted to extend into the water flowing from the connection 40 through the housing and out through the supply conduit 62. The bulb 64 is operably connected, as through a tube 66, to the control mechanism 68 of the steam flow regulator 33; and thus, according to the setting of the valve control device, the supply of steam entering the tubes of the heating unit 18 will be automatically regulated to insure the delivery of water through conduit 62 at the required temperature. It will be readily understood that whenever the outlet 62 is drawn upon, water previously heated by the lower unit and stored in the tank will now flow in reverse direction through the upper heating unit, and therefore when delivered it will be at a temperature higher than the temperature of the water available at outlet 15.

It is a particular feature of the present invention that through use of a single storage tank and a plurality of heating units arranged in the specific relationship illustrated and described hereinabove, substantial installation investment and operating economies may be realized, When compared to any equivalent output dual tank and heater system. This is because the usage demands on the high and low temperature outlets of the system do not normally coincide, and therefore it is feasible to use a single storage facility both for the low temperature supply and as a pro-heat supply for the water to be flash-heated to higher temperature when passing to the high temperature water outlet. For example, it has been ascertained that an apparatus of the present invention employing a single tank of 2500 galloncapacity and working on 40 F. feed water may be designed and control-set to supply 140 F. water (as at 15) at the rate of 1000 gallons per hour, and 180 F. water (as at 62) at 1000 gallons per hour; thereby matching the performance capabilities of a dual tank system employing a 1000 gallon tank and heater for heating 140 F. water alone and a 2000 gallon tank and heater for heating 180 F. water alone. The improved system performance is also atributable in part to the optimized heat exchange and heat storage efiiciencies due to the substantial submergence of both heating units in the single body of storage water.

Whereas the system illustrated herein employs a pair of return-bent tube bundles using steam as the heat source, it is to be understood that any other type of heat source and/or heat exchange mechanism may be employed such as electrical heating elements or the like. Hence it will be appreciated that although only one specific form of heating system has been shown and described herein, various changes may be made therein without departing from the spirit of the invention and the scope of the following claims.

I claim:

1. A water heating and storage device comprising the combination of,

a single container in which heated water is stored,

a low temperature heated water outlet in communication with said water in said container,

a first water heating device comprising a housing extending into said container and arranged in communication adjacent its outer end with a cold water supply conduit and having a heated water discharge opening at its inner end for delivery of heated water to the interior of said container,

said outer end of said housing being closed to the passage of water from within said housing,

a first water heater disposed Within said housing in heat exchange relation with water therewithin in its passage from the supply to said discharge open.- mg,

a first water temperature sensor in communication with the water heated by said first water heater,

a first heater energizing control device connected to said first water heater for control of the latter,

means operatively interconnecting said sensor and said heater control device to regulate the operation of said first water heater in accord with water temperature variations in the region of said sensor,

a second water heating device comprising a second housing extending into said container and open at its inner end to the passage of heated water from said container but closed at its outer end,

a second water heater disposed in said second housing in heat exchange relation with water therewithin,

high temperature heated water outlet conduit in direct communication with the outer end portion of said second housing,

a second water temperature sensor disposed in the region of said high temperature heated water outlet conduit,

a second heater energizing control device connected to said second heating device for control of the latter,

and means operatively interconnecting said second sensor to regulate said second heater in accord with water temperature variations in the region of said sensor.

2. A device as set forth in claim 1 wherein said first heating device extends partially into the lower portion of said container and said second heating device extends into the upper portion of said container.

3. A device as set forth in claim 2 wherein said low temperature heated water outlet connects into said container at a portion thereof remote from said second heating device.

4. A device as set forth in claim 1 including means operating to cause continuous circulation of water from interiorly of said container into the outlet end portion of said first housing and thence through said housing to contact said first heater and back into said container.

5. A device as set forth in claim 1 wherein said second water temperature sensor is disposed in said high temperature heated water outlet conduit.

6. A device as set forth in claim 1 wherein said first sensor is located in the open body of said container.

7. A water heating and storage device for holding warm water at a predetermined temperature and adapted to supply such warm water immediately upon demand which may be intermittent and to supply also hot water of a higher temperature immediately upon demand which may be intermittent, the demands for warm water and hot water not necessarily being related, said device comprising, in combination,

a container for storage of heated water,

a warm water outlet connected to said container,

a water inlet heater for discharging freshly heated warm water into the interior of said container, said water inlet heater including a housing extending into said container and terminating therewithin a discharge m-outh, a fresh water inlet connected to said housing remote from said discharge mouth, and heater means within said housing between said fresh water inlet and said discharge mouth whereby fresh water entering said container through said housing is heated by said heater means,

means for controlling said heater means to maintain a uniform warm water temperature within said container and including means for continuously recirculating Warm water from said container through said housing and back into said container through said discharge mouth,

a second water heater for withdrawing hot water from the interior of said container, said second water heater including a second housing extending into said container and terminating in an inlet mouth, a hot water outlet connected to said second housing remote from said inlet mouth, and second heater means within said second housing between said inlet mouth and said hot water outlet whereby warm Water withdrawn from said container through said inlet mouth is heated by said second heater means,

and means adjacent said hot water outlet for controlling said second heater means to maintain a uniform temperature for hot water discharged through said hot water outlet.

8. A water heating and storage device for holding warm water at a predetermined temperature and adapted to supply such Warm Water immediately upon demand which may be intermittent and to supply also hot Water of higher temperature immediately upon demand which may be intermittent, the demands for warm and hot Water not necessarily being related, said device com-prising, in combination,

a container for storage of heated water,

Within said housing between said fresh Water inlet and said discharge mouth whereby fresh water entering said container through said housing is heated by said heater means,

means for controlling said heater means to maintain a uniform warm water temperature Within said con tainer and including means for continuously recirculating warm Water from said container through said housing and back into said container through said discharge mouth,

second water heater for withdrawing hot water from the interior of said container within a region thereof remote from both said discharge mouth and said Warm water outlet, said second water heater including a second housing extending into said container and terminating therewithin in an inlet mouth spaced from both said warm Water outlet and said discharge mouth, a hot water outlet connected to said second housing remote from said inlet mouth, and second heater means within said second housing between said inlet mouth and said hot water outlet whereby warm water withdrawn from said container through said inlet mouth is heated by said second heater means,

and means adjacent said hot water outlet for controlling said second heater means to maintain a uniform temperature for hot water discharged through said hot water outlet.

References Cited UNITED STATES PATENTS 2,834,865 5/1958 Coates 21938 a warm water outlet connected to said container, 2 879 749 3/1959 Lewy a water inlet heater for discharging freshly heated 2969451 1/1961 Logan X Warm water into the interior of said container, said 9/1962 fi g y t water inlet heater including a housing extending into 3:13 :5 0 5 1964 Lowe {5 .X said container and terminating therewithin in a dis- 3,2 7 4 3 19 Morgan 165.49

charge mouth spaced from said warm Water outlet, a fresh water inlet connected to said housing remote from said discharge mouth, and heater means ROBE-RT A. OLEARY, Primary Examiner. M. A. ANTONAKAS, Examiner. 

7. A WATER HEATING AND STORAGE DEVICE FOR HOLDING WARM WATER AT A PREDETERMINED TEMPERATURE AND ADAPTED TO SUPPLY SUCH WARM WATER IMMEDIATELY UPON DEMAND WHICH MAY BE INTERMITTENT AND TO SUPPLY ALSO HOT WATER OF A HIGHER TEMPERATURE IMMEDIATELY UPON DEMAND WHICH MAY BE INTERMITTENT, THE DEMANDS FOR WARM WATER AND HOT WATER NOT NECESSARILY BEING RELATED, SAID DEVICE COMPRISING, IN COMBINATION, A CONTAINER FOR STORAGE OF HEATED WATER, A WARM WATER OUTLET CONNECTED TO SAID CONTAINER, A WATER INLET HEATER FOR DISCHARGING FRESHLY HEATED WARM WATER INTO THE INTERIOR OF SAID CONTAINER, SAID WATER INLET HEATER INCLUDING A HOUSING EXTENDING INTO SAID CONTAINER AND TERMINATING THEREWITHIN A DISCHARGE MOUTH, A FRESH WATER INLET CONNECTED TO SAID HOUSING REMOTE FROM SAID DISCHARGE MOUTH, AND HEATER MEANS WITHIN SAID HOUSING BETWEEN SAID FRESH WATER INLET AND SAID DISCHARGE MOUTH WHEREBY FRESH WATER ENTERING SAID CONTAINER THROUGH SAID HOUSING IS HEATED BY SAID HEATER MEANS, 